The use of a cartridge for storing a viscous material is known. Such cartridges are often configured to be used with an actuator for directing the dispensing from the cartridge. The known cartridges are often formed by a cylindrical tube having a substantially rigid outer shell and a nozzle at one end. A moveable piece or plunger cup is located within the end opposite of the nozzle. The plunger cup is pushed towards the nozzle within the tube by the actuator to force the material from within the cartridge through the nozzle.
U.S. Pat. No. 4,342,408 to Boring discloses a caulk cartridge having a separate nozzle member that seals with the end wall of the cartridge tube. The nozzle includes an enlarged annular base that engages with the inside surface of the end wall, when positioned within an opening in the end wall. The pressure from the caulk material forces the base of the nozzle into engagement with the end wall to seal the opening. Caulk is directed through the nozzle.
U.S. Pat. No. 2,587,683 to Barry discloses a disposable caulking gun. The gun is formed by a tubular container that is adapted to carry an ejection key and a nozzle prior to use. The ejection key is threaded into the back of the container and is used to drive an internal plunger to expel the material through the nozzle attached to the opposite end of the container.
U.S. Pat. No. 5,137,184 to Jackson et al. discloses a disposable cartridge that is inserted within a caulking gun for dispensing the stored material through a removable nozzle. The nozzle is fixed to the cartridge during positioning of the nozzle and cartridge within the gun structures.
Typical actuators for directing the dispensing of material from a cartridge include a front portion that engages the front end of the cartridge and a plunger is located at the rear of the actuator. The plunger is incrementally moved towards the front end of the actuator and pushes the plunger cup within the cartridge towards the front of the cartridge. The movement of the cup forces the material stored within the cartridge through the nozzle at the opposite end.
Often the actuator resembles the shape of a gun, with a base portion formed to retain the cartridge, a holding handle and a trigger extending below the base for actuating movement of the plunger. Numerous variations of the interaction between the trigger and the plunger are known. Generally, a rod with teeth is provided for supporting the plunger. A ratcheting mechanism engages the rod teeth with the trigger creating the incremental movement of the plunger.
U.S. Pat. No. 4,356,938 to Kayser discloses a caulking gun having a pressure release mechanism. The release of the pressure stops the flow of caulk from the cartridge.
U.S. Pat. No. 5,875,920 to Parent discloses a caulking gun that is reduced in length and accepts a cartridge with a tube length of approximately one half the length of a conventional caulk tube.
U.S. Pat. No. 6,672,489 to Huang discloses a caulking gun with a ratchet push rod. The ratchet mechanism allows the push rod to move backward after the trigger moves it forward. The backward movement reduces pressure in the tube to prevent excess discharge of the stored material at the end of the actuated movement.